Electrical thermostat



NGOLDSTEIN.

ELECTRICAL THERMOSTAT.

APPLICATION FILED 0619,1915.

1,328,427 Patented Jan. 20, 1920.

I I I I I I I f,

ip/R \1\ x 4 WITNESSES. INVENTOR 'hw w W To all whom it-inay concern: a

ALBERT GOLDS'I'EIN, or NEW'YORK, N. Y., AssIGNoR 'ro' SIMON B. Hess, OF NEW YORK, N. Y.

,. ELECTRICAL'THE'RMOST'AT.

Specification of Letters Patent. I Pat nt Jam 20,192

Original w-"ution' filed November isfislt, Serial No. 872,680. Divided and this application filed October Be it'known that I, A 'LBE RT GOLDSTEIN; a citizen of the United States, residing at 2508 Broadway, in the city ofNew York, county of-New York, and State-ofNeWYOrk, have invented certainnew and useful Improv ments in Electrical Thermostats, offlwhiclr -the following is .a full. clear, and exact description. I I My invention relates to thermostatic devices of the type in which air expansion in a closed chamber actuates a-diaphragm to close a circuit and t ransmit an'al'arm signal,

' and a method for adjusting the thermostat of a thermo'statwhereby the instrument is y to operate at apredetermined rate of temperature rise. 0 The lnvention consists in the construction made highly sensitivetoslight changes in the temperatureof the surrounding atmosphere, said thermostat having a" vent to 'equalize'the internal with the external pressure when due'to gradual and slow temperature changes but which provides; a frictional impedance to the passage of'the air out of" the instrument when the increase 'of' res- .sure and volume is due .to a'rapid tempera? .ture rise, this pressure equalization being accomplished by a leakage through a screw threaded. joint.'means being provided fol-securely locking the said joint in position and sealing-the instrument when said position.

from the diaphragm case 2 by the mica link 1 has been ascertainedby test. v

In the accompanying drawing, I ,have illustrated an embodiment of my present preferred form. i

Referring to the .drawing,- the lower half, 1 of the diaphragm case constitutes the upper part of the pressure chamber and is secured to the upper half of the.-diaphragm case 2'- by the-clamping. ring 3 and constitutes the temperature responsive element of the device, at the same time affording a means of. support for the remaining parts of the pressure chamber through the vent socket 4 by which by means of the vent'scr'ew g"), the air chamber 6 is held in place.

' In the upper half 2 of the diaphragm case is placed the contact screwlbody f7 secured by the nut 8 and washer 9, and within which is'placed the contact screw '10, all insulated 11 and theinsulating-bushing and electrically connected by the metal link 12 to by the washer l4 and lated from itby the mica link 11 and the insulating bushing 24:. 13' is in mechanical and electrical connecof the locking screws 18 and 18.

21 and 21'. v v

Between the upper half 2 ofthe dia- "'-The screw thread joint 9, 1915. Serial No. 55,100.

the connecting stud-13, which also secured to the upper half 2 ofthe diaphragmlcase the nut 15 and insu-' The connecting stud' tion with the upper half 2 of the diaphragm,

c ase, being securedthereto by a nut similar .to 15, both connecting studs afi'ording means for electrical connection through the medium of the metal blocks I17- and-. 17' mountedin the insulating support 16. I The connectingstuds are provided with grooves around their bodies near their "free extremr tiesalfording engagement for the extremity The circuit'wires are held in secure electrical contact with the metal blocks 17 and 17' by the binding screws 20 and 20 and the'washers phragm case and the-lower half 1' of the case, 18 placed a diaphragm 22' of thin sheet copper or .other suitable material, secured by the clamping ring 3 which also holds the two parts of the diaphragm case securely 1n flace.

he following is the method of adjusting the air vent of the'thermost-at so that the air contained withln the expansion or pressure chamber may beallowedto escape to the outer atmosphere'thro'ugh the tortuous passage formed by.the,space between the male and female elements of the supporting screw parts when the rate .of increase-in volume I due to temperature rlse below a certaln predetermined number of degrees per. minute is experienced.

between the vent;

socket 4 and the vent screw-54s made to.

standard screw thread sizes, affording suf= ficient space between the twoelements of thescrewed partsto permit the escape of air from within the pressure or expansion chamber when subjectedto pressure; The-pres sure" foradjusting purposes isfapplied at a small opening-in the lower half'l of the diaphragm case,. plug 26.

The adjustment may "be efi'ected for a critical rate of temperature rise of three degrees F. per minute, .for example, a more rapid rise deflecting the diaphragm and Op:

shown as sealed with the erating a circuit closer. -'T-his rate of rise proximately 2.2 inches 'of water.

of air flow through the vent may be adj-usted by varying the length ofthe tortuous passage between the male thread onthe vent means of a water gage and pressure chant.

ber connected to the opening for a plug 26 (later sealed). In the case just assumed,

with a room temperature of seventy degrees F, a rise oftemperature of three degrees Wl'll cause an increase ot pressure of ap- The rate screw 5 and the female thread in-the vent socket et by advancing or withdrawing the vent screw 5 until the rate which will barely allow the pressure to remain at inches without causing the defiectionof the dia-' phragm is arrived at, after which the two 'parts of the ven tthe vent socket 4 and the vent screw 5 a re locked in position bya pin 25 driven into a drill hole and-cut ofi' flush with the surface of the ventsockett.

The operation of the thern'lostatis as fol lows': The contact screw 10 is preferably jadjusted so that. its tip comes as close to the diaphragm 22 as possible without touching it; but it may be adjusted at any predetermined distance from said diaphragm dependent upon the conditions under which it is desired to work. llhe increase'and decrease in the pressure of air within the chamber6 and its relatedparts as affected by the changes of ten'iperatu're are normally equalized with that the surrounding at- I mosphere through the vent space between .the vent socket 4 and the vent screw 5 so that there is no danger ot'the apparatus being set 1n operation from the effect of gradual changes of temperature. Should, however,

or pressure chamber must pass.

socket 4 .a quick rise in the case of a fire, in which the increase in the temperature of the surrounding air would be greater than, for example, the three degrees assumed that the instrument is adjusted to operate, the heat is rapidly conducted through the walls of the chamber 6 expand.

ing the air therein more rapidly than the vent in the screw parts ant 5 will permit it to escape, and the increasing volume and pressure is communicated to-the surface of. dlstendmg 1t and the flexible diaphragm, causing it to make an electrical contact with the contact screw 10.

.No electric circuit for the thermostat is herein shown or described, but a circuit which may be used. is. shown in .my co endin temperature take place, as

F. .per. minute at which it" is ing application filed Nov. 18, 191+ erial No. 872,680, ot which application this application is a -div1sion.-

I claim:

1. An electrical thermostat comprising a case, a diaphragm in said case dividingthe space therein into two-chambers, a contact piece iii proximity to the diaphragm in one of said chambers, the contained air in said chamber being freely open to the atmosphere,

an expansion chan'iberconnected to the other of said two chambers, and an adjustable vent, the adjustment of said vent being secured by the manipulation of a screw oint by means of which'theexpansion chamberis attached to sa1d other chamber.

2rnln a thermostatic device, a

able vent, the adjustment of said vent being secured by the manipulation of a screw omt by means of wlnch'theexpansion chamber is attached to the diaphragm ca se.

In testimony whereof I have atliXed iny signature in the presence oftwo witnesses. r

I ALBERT GOLDSTEIN \Vitnessesz a MI NIE Newman, BELLE HAMMER.

diaphragm case, an expansion chamber, and an ad ust- 

